Some people have an excess of teeth, called hyperdontia. The prevalence of supernumerary teeth in the population varies from 0.1 to 4%. They are less common in the deciduous dentition. Hyperdontia is usually due to genetic causes. It is also seen in certain developmental disorders like Gardner’s Syndrome and cleidocranial dysostosis. When multiple supernumerary teeth are present, they often do not erupt, but remain impacted in the jaw bone due to a lack of space in the mouth. Those that manage to erupt into the mouth often are displaced or crooked, because the mouth can only accommodate a limited number of teeth.
Sometimes, excess teeth are only discovered during routine dental X-ray examination as they remain buried in the jaws, hidden from view.
See also: Gum pigmentation